The recent rapid growth of information applications on international public packet-switched computer networks such as the Internet suggests that public computer networks have the potential to establish a new kind of open marketplace for goods and services. Such a marketplace could be created with a network sales system that comprises a plurality of buyer and merchant computers, means for the users of the buyer computers to display digital advertisements from the merchant computers, and means for the users to purchase products described by the advertisements.
A network based sales system will need to allow users to preview products at little or no cost, and will need to make a large number of product advertisements available in a convenient manner. In addition, the shopping system will need to include easy-to-use facilities for a user to purchase desired products using a merchant independent payment method. In addition the network sales will need to allow new buyers and merchants to enter the market.
A central requirement for a marketplace is a payment mechanism, but at present no merchant independent payment mechanism is available for computer networks that permits users to utilize conventional financial instruments such as credit cards, debit cards, and demand deposit account balances. We expect that both retail payment and wholesale payment mechanisms will be required for networks, with consumers using the retail mechanism for modest size purchases, and institutions using the wholesale mechanism for performing settlement between trading partners. For wide acceptance the retail mechanism will need to be a logical evolution of existing credit-card, debit-card, and Automated Clearing House facilities, while for acceptance the wholesale mechanism will need to be an evolved version of corporate electronic funds transfer.
These problems of have been approached in the past by network based sales systems wherein, for example, each merchant maintains an account for each user. A user must establish an account with each merchant in advance in order to be able to utilize the merchant. The prior art network based sales systems are not designed to allow users to use their existing credit card and demand deposit accounts for payment, nor are they designed to allow for programs to be included in digital advertisements.
According, therefore, it is a primary objective of this invention to provide a user interactive network sales system in which the user can freely use any merchant of choice and utilize existing financial instruments for payment. Other objects include a network sales system which provides a high-quality user interface, which provides users with a wide variety and large volume of advertisements, which is easily extensible to new services, and which is easily expanded to new applications within the existing infrastructure of the system.
Still other objects of the invention are to provide a network payment system that will authorize payment orders and remove part of the risk of fraud from merchants.
An unavoidable property of public computer networks is that they are comprised of switching, transmission, and host computer components controlled by many individuals and organizations. Thus it is impossible for a network payment system to depend upon a specified minimum required degree of software, hardware, and physical security for all of the components in a public network. For example, secret keys stored in a given user's personal computer can be compromised, switches can be tampered with to redirect traffic, and transmission facilities can be intercepted and manipulated.
The risk of performing retail payment in a public network is compounded by statutes that make a payment system operator in part liable for the security lapses of its users. Existing Federal statutes in the United States, including the Electronic Funds Transfer Act and the Consumer Credit Protection Act, require the operator of a payment mechanism to limit consumer liability in many cases. Payment system operators may have other fiduciary responsibilities for wholesale transactions. Similar responsibilities exist in other countries for retail and wholesale transactions.
In existing credit card payment systems, a credit card's issuing bank takes on the fraud risk associated with misuse of the card when a merchant follows established card acceptance protocols. Acceptance protocols can include verifying a card holder's signature on the back of their card and obtaining authorization for payments over a certain value. However, in network based commerce a merchant can not physically examine a purchasers credit card, and thus the fraud risk may revert to the merchant in so called "card not present" transactions. Many merchants can not qualify to take this risk because of their limited financial resources. Thus the invention is important to allow many merchants to participate in network based commerce.
Other objects of the invention include utilizing existing financial instruments such as credit cards, debit cards, and demand deposit accounts for merchant payments.
Existing network payment systems do not connect to the financial system for authorization and are not compatible with conventional financial instruments. Existing network payment systems include the Simple Network Payment Protocol [Dukach, S., SNPP: A Simple Network Payment Protocol, MIT Laboratory for Computer Science, Cambridge, MA, 1993.], Sirbu's Internet Billing Server [Sirbu, M. A., Internet Billing Service Design and Prototype Implementation, Information Networking Program, Carnegie-Mellon University, 1993], and NetCash [Medvinsy, G., and Newman, B. C., NetCash: A Design for Practical Electronic Currency on the Internet, Proc. 1st ACM Conf. on Comp. and Comm. Security, November, 1993].
A further object of the invention is to allow users in an untrusted network environment to use conventional financial instruments without requiring modification to existing financial system networks.
The following definitions apply to the present invention. A principal is a person, company, institution, or other entity that is authorized to transact business as part of a network payment system. A payment order describes the identity of a sender, a payment amount, a beneficiary, and a sender unique once. A sender is a principal making a payment. A beneficiary is a principal to be paid by the payment system. A sender unique nonce is an identifier that is used only once by a given sender. An example of sender unique nonces are unique timestamps. An external account is an account that can be used to settle a payment order for either a sender or a beneficiary in the external financial system. Examples of external accounts include demand deposit accounts and credit card accounts. An external device is a physical object that is kept in the possession of a user for the purpose of identifying the user.
A network payment system is a service that authorizes and executes digital payment orders that are backed by external accounts. A payment system authenticates a payment order, checks for sufficient funds or credit, and then originates funds transfer transactions to carry out the payment order. A payment system acknowledges acceptance or rejection of a payment order. More than one payment system may exist on a given network, and a given payment system may operate on more than one host to increase its reliability, availability, and performance. An authenticator is a digital value that is appended to a payment order and becomes part of the payment order that authenticates the payment order as genuine.